Partial support is requested to allow an investigator established in engineering research to explore promptly the feasibility of a novel approach to high-speed gamma radiation detection for application to biomedical research using time-of-flight positron-emission tomography. The detector to be developed, constructed, and tested would utilize BaF2 crystals, microchannel plates, and a specially designed amplifier to achieve very fast detection of positron-electron annhilitations. Substantial reduction in timing uncertainties over that of current state-of-the-art detectors is projected to result from a compound configuration using multiple crystals, which would be rendered practicable through the use of microchannel plates as physically thin and very fast photomultipliers. A fundamental limitation of microchannel plates for such use would be overcome by a specially designed high-bandwidth amplifier. A number of very difficult design problems will have to be solved in order to establish the feasibility of the method. A recent international Workshop on Time-of-Flight TOmography underscored the importance of fast photon detection as a major limitation in prototypic systems under development. Projected benefits would derive from improved images thus allowing better clinical studies with lower radiation doses and/or more precise dynamic tracking of tracer uptake as well as improved imaging of moving organs such as the heart.